Have a song stuck in your head and can't figure out what it is? Hear a hot song on the radio but the DJ doesn't say the title? How about a backing track in a video that you like? Google Assistant now features a fantastic new tool allowing you to search for any song by audio. Even something as inaccurate as humming the tune can turn up accurate results. And what's best? It has already been added to your Android phone: There's no app to install, and it's absolutely free.